Given a navigation instruction \(w\) , we first utilize state-of-the-art natural language processing (NLP) tools to parse its grammatical structure. Assuming that \(w\)  takes a simple form that only specifies the destination, such as “go to the meeting room near the north exit”, we first perform semantic role labeling [1]} to extract the noun phrase that describes the destination. Then, our goal is to ground the destination, “meeting room near the north exit”, to a specific area \(a^*\)  on the map that can be fed to downstream path planning modules. The key to achieving this goal is to view the noun phrase as constructing a chain of spatial relationships that points to the final destination. In the following sections, we provide a formal explanation and build a recursive belief update algorithm that utilizes the grammatical structure of destination noun phrases.
